An experienced, analytically trained psychotherapist was physiologically monitored while conducting a 28-session exploratory psychotherapy with a patient suffering a pathological grief reaction. The therapist's autonomic responses, as manifested by perturbations in heart rate, were subjected to nonlinear dynamical analysis, yielding a series of characteristic “trajectories” representing the flow of these responses in time. We report interrater reliability and present descriptive statistics resulting from classifying these trajectories into four types. Interesting but preliminary clinical correlates of these autonomic trajectories were obtained by having the therapist review videotaped excerpts of the sessions and complete a self-report questionnaire. In conjunction with a previous report focusing on autonomic responses in the patient, this study further demonstrates the application of nonlinear dynamical methods to investigations of psychophysiology in the setting of psychotherapy, and perhaps in dyadic interactions more generally.